I have already made a very successful A5 sized ATS but for my new larger tank I have all but finished a new A4 sized ATS. My ATS will sit in the sump, however as the compartment I wanted to fit it in was a little narrow I had to devise a way of getting over it so I doglegged the RH LED unit over the glass baffle. The scrubber box and 2 lights can all lift off independently from the "rig" I made which can stay in the sump should I need to remove the lights, screen or box. I used 22mm pipe and an A4 leaflet let box to house the scrubber screen in. Lighting is by 2 x 20w Chinese hydroponics plant lights with 16red aand 4 blue LED's. I have removed one light so as to get a better view of the ATS here.